This invention relates to audio-visual apparatus for the simultaneous viewing of photo-images and audio production of a lecture or commentary relating thereto and more particularly to such an apparatus which may be controlled by the user to select any one of a group of photo-images for viewing or to sequentially view the photo-images of such group in any desired order with the audio production of the lecture or commentary relating to each photo-image being automatically selected from a corresponding group of sound recordings.
The prior art provides apparatus of various kinds for the simultaneous viewing of photo-transparencies and audio production of sound associated therewith. The most crucial feature of any such apparatus is, of course, to obtain proper synchronization between the presentation of the photo-transparency for viewing and the production of the sound.
The apparatus used for presenting motion pictures with accompanying sounds is a well known example of the broad concept. However, it will be understood that such apparatus must be designed to present a large number of photo-transparencies in fixed sequence and rapid succession, each in conjunction with the production of a relatively short segment of sound from a sequentially recorded series of sounds or "sound track." In every instance a number of slightly different photo-transparencies will be presented in connection with sounds comprising a single word of human speech.
It is an object of this invention to provide apparatus in which an extended dialogue or portion of a lecture or commentary is produced in conjunction with the presentation of a single photo-image for extended viewing. Thus, techniques and apparatus suitable for the presentation of motion pictures with sound are not applicable in accomplishing the objects of this invention.
Others have designed apparatus for use in advertising or in the presentation of travelogues or for instructional purposes in which a series of photo-transparencies are presented for viewing in conjunction with the audio production of an extended segment of a recorded sound track comprising a dialogue, lecture or commentary. However, in such apparatus the synchronization between the sound track and the presentation of the photo-transparencies has been accomplished by providing for the sound track to control the presentation of the photo-transparencies in fixed sequence. See, for example, U.S. Pat. No. 3,048,083 to Rosenbaum.
The magnetic tape, of course, need not be endless as disclosed by Rosenbaum and in some devices of the general type the mechanism is not automatic. Instead, the control signal is produced as an audible sound to remind the operator to advance the photo-transparencies from one to the next in the fixed sequence.
Similar results have been obtained in apparatus of the type in which the dialogue, lecture, or commentary is recorded on conventional disc type records as described in U.S. Pat. No. 3,138,061 to Greenway, for example. In such apparatus, a control signal may be recorded on the disc and used in the same way as described above. However, as disclosed by Greenway, it is also possible to utilize the changing angular position of the tone arm as it moves across the record to control the presentation of the photo-transparencies in fixed sequence.
It is another object of this invention to provide apparatus of the type broadly described above in which the presentation of a photo-image from a group thereof automatically selects for production a particular portion of a sound track corresponding to such group of photo-images. Thus, prior art apparatus as disclosed by Rosenbaum and Greenway in which the sound track controls the presentation of the photo-transparencies is not applicable in accomplishing the objects of this invention.
It will be understood that in all apparatus of the prior art as discussed above, the presentation of the photo-transparencies and the production of sound must occur in a fixed time sequence. Thus, a certain amount of time is allowed for viewing each photo-transparency which amount of time is controlled by the sound track. In order to view a particular photo-transparency for a longer or shorter period of time than that allowed by the established time sequence, it would be necessary to interrupt the normal operation of at least the sound system of the apparatus thus tending to interfere with the synchronization between the sound track and the sequence of photo-transparencies.
U.S. Pat. No. 3,484,160 to Glass et al discloses an audio visual toy in which visual presentations may be viewed for any desired length of time independently of the audio presentation associated therewith. However, in using audio-visual apparatus of the type described above for instructional purposes, it is highly desirable that the person who seeks instruction be able to interact with the apparatus. If the user of the toy taught by Glass et al attempts to interact with the device by viewing the visual presentations out of their normal order, the synchronization between the visual presentation and the audio presentations will be destroyed.
In order to provide optimum interaction between the apparatus and the person seeking instruction from it, it is necessary that such person be able to control the sequence in which the photo-transparencies and the sound corresponding thereto are presented. It will be seen that in the apparatus of the prior art it is highly inconvenient, if not impossible, for the user to vary the order of the sequence of the presentation without destroying the synchronization between the sequence of the photo-transparencies and that of the sound track.
It is a still further object of this invention to enable full interaction between audio-visual apparatus of the type described and a person seeking instruction by providing apparatus which may be operated in a substantially random access mode under the control of such person.
It is often desirable to present two or more different things for comparative viewing in order to instruct persons as to similarities or differences between such things. It is also desirable that such things be clearly presented to the viewer and often desirable that they be presented stereoscopically so that differences or similarities in form may be seen. Finally, it is often desirable in such situations to direct the attention of the viewer first to one and then to another of two or more things presented for viewing.
It is another object of this invention to provide a stereoscopic viewing system based on the use of two identical views of a particular field of vision in order to provide clarity of view, apparent depth perception, and optical separation between fields of vision to facilitate comparative viewing of different things.
In order for audio-visual apparatus to be useful for instructional purposes, it is necessary that such apparatus be simple and convenient to operate, small, rugged and lightweight for portability, and inexpensive to manufacture and maintain. It is yet another object of this invention to provide apparatus of the type described based on the use of disc type records for sound recording which are mounted in rugged units for storage and use, whereby the mechanism of such apparatus is inexpensive to manufacture and maintain, small, lightweight and rugged for portability and convenient to operate.